REAKINGS AND DISSECTIONS OP TACHINIDJE. 



103 



EUPELETERIA MAGNICORNIS Zetterstedt. 



One of the next species taken up was Eupeleterki nuujnieornis Zett., 

 Avhicli proved to l)e most i-eniarkable as regards startling deviations 

 from the previonsly known manner of reproduction among tachinids. 

 The females of this species were most carefully labored with for a 

 Aveek or more in the attemj^t to secure their oviposition, using all 

 kinds of caterpillars available. All efforts were in vain. Some dead 

 females had been dissected and found to contain elongate, whitish, 

 slightly curved eggs. It was not realized at the time that these 

 females were immature so far as the development of the eggs in the 

 uterus was concerned, and thus it was inferred that the species would 

 deposit large elongate eggs on the cat- 

 erpillars. It seemed quite inexplicable, 

 therefore, when the females proved to 

 be as nuicli alarmed at the close prox- 

 imity of caterpillars as were the fe- 

 males of Blepharipa scutellata, Pales 

 2?arida, and ZeniUia I'lbatrix. From 

 the nature of the eggs it was impos- 

 sible that they could be deposited on 

 the leaves and eaten by the caterpillars. 

 But why, then, should the females be 

 so alarmed when brought face to face 

 with the caterpillars? After much 

 patient observation and experiment 

 this question was answered. The flies 

 were found to deposit living maggots, 

 not on or in the caterpillars, l)ut, most 

 remarkable to relate, on the green 

 shoots, leaf-stems, leaf-ribs, and even 

 sometimes on the surface of the leaves ! 



The females would hover in the 

 air about the shoots after the man- 

 ner of syrphid flies, looking for caterpillars. They gave pref- 

 erence to the stems in depositing their maggots, and usually placed 

 them where a silken thread had been left by a caterpillar as it 

 climbed along a stem or over a leaf. Perhaps the sense of smell 

 guided them in their larviposition on these silken threads. Several 

 species of caterpillars Avere used Avith equal success, and it Avas found 

 that the females Avould not deposit their maggots on shoots Avhere 

 caterpillars Avere not present. In fact it seemed necessary that cater- 

 pillars should have first craAvled over the stems and leaves. The 

 maggots are securely attached to the surface of the leaf or stem at the 

 moment of deposition, by a thin membranous case.Avhich is cup-shaped 





Fi(!. '11. — Eiipelcteria magiiicornis: 

 a. First-stage maggot attached to 

 leaf, awaiting approach of a 

 caterpillar ; b, enlarged mouth- 

 hook of maggot, o, Greatly en- 

 larged ; b, highly magnified. 

 (Original.) 



